The evolving networks and new types of mobile terminals, particularly smart phones, are gradually changing the characteristics of mobile traffic. There are more and more applications requiring always-on type of connections. Such a trend gives rise to a number of challenges both in the radio access network load as well as challenges relating to, for example battery drain, in mobile terminals. For example, the network may experience signaling load issues caused by a large number of connected mobile terminals or mobile terminals constantly changing state between idle and connected.
Mobile terminals, such as smart phones, generate traffic even while unattended by a user simply because certain applications are currently executing. For example, applications that include social networking (e.g. Facebook), instant messaging (Nimbuzz, Skype) or the like may generate status updates, polling, keep alive or similar traffic even when the applications are not actively being used. The traffic typically consists of small packets (or bursts of packets) sent intermittently. Also different operating systems (OS) may check various updates regularly.
Despite being “always-on” a mobile terminal's power consumption may be close to the idle mode power consumption when services are not actively used. For example, a mobile terminal may be configured with (long) discontinuous reception (DRX), or they may be in an idle state between the data bursts allowing sufficient “sleep” times for the mobile terminal.
In long term evolution (LTE) networks the state transitions, DRX configuration and the usage of Physical Uplink Control Channel (PUCCH) resources are controlled by the network. Thus, the LTE networks attempt to achieve the optimum operation both from the mobile terminal and network perspective.